Taggant systems with remotely detectable spectral signatures

A spectral signature system, comprising:

• a) a multilayer taggant particle, wherein the multilayer taggant particle comprises:
• 1) an opaque base layer comprising first and second opposed major faces;
• and
• 2) at least a first spectral taggant layer provided on at least one of the first and second opposed major faces, wherein the first spectral taggant layer comprises a light transmissive matrix and one or more luminescent taggants dispersed in the light transmissive matrix, and wherein the taggant particles exhibit a luminescent emission comprising spectral characteristics associated with a spectral signature;
• b) a spectral signature associated with the spectral characteristics of the taggant system, wherein the opaque base layer provides a solid background against which the spectral signature is produced and read;
• c) a multispectral imaging device configured to capture multispectral image information of a scene;
• and
• d) a control system that uses information comprising the captured multispectral image information to determine an output indicative of a detection and/or a location of the spectral signature in the scene.

A method of remotely detecting a spectral signature in a scene, comprising the steps of:

• a) providing spectral signature that is pre-associated with the spectral characteristics of at least a first plurality of first, multilayer taggant particles, wherein each of the first multilayer taggant particles comprises:
• 1) an opaque base layer comprising first and second opposed major faces;
• and
• 2) at least a first spectral taggant layer provided on at least one of the first and second opposed major faces, wherein the first spectral taggant layer comprises a light transmissive matrix and a taggant system comprising one or more luminescent taggants dispersed in the light transmissive matrix, and wherein the taggant system exhibits a luminescent emission comprising the spectral characteristics associated with a spectral signature;
• and
• 3) wherein the opaque base layer provides a solid background against which the spectral signature is produced and read:
• b) capturing multispectral image information of a scene remotely from a distance;
• and
• c) using information comprising the multispectral image information to determine an output indicative of the detection and/or location of the spectral signature in the scene.